NPL announces two collaborative projects with industry

Soldering & Surface Mount Technology

ISSN: 0954-0911

Article publication date: 1 August 2000




(2000), "NPL announces two collaborative projects with industry", Soldering & Surface Mount Technology, Vol. 12 No. 2.



Emerald Group Publishing Limited

Copyright © 2000, MCB UP Limited

NPL announces two collaborative projects with industry

NPL announces two collaborative projects with industry

Keywords NPL, Benchmarking, Solder paste, Measurement, Finishing, Components

The National Physical Laboratory is launching two collaborative projects, known as "Studio Projects", one to benchmark measurement systems for solder paste deposits, the other to benchmark component finishes.

Solder paste printing is generally thought to account for around two thirds of solder defects located after soldering. As component pitches become finer, the quality of the paste deposit becomes increasingly important. A number of systems covering various solder paste measurements are now available and some stencil printer manufacturers have incorporated systems into their printers. "The measurement of printed solder paste deposits" is a project intended to investigate the options available for paste measurement and benchmark them with a series of tests which will assess the capabilities of the systems available. A report will be available on completion.

With the move to eliminate lead from the electronics manufacturing process, a project is launched to assess the processability of the new lead-free component finishes. The project will benchmark the finishes in a series of tests. The plating chemistry suppliers are currently developing a range of alternative Pb-free finishes for use on component terminations. These include: pure tin; alloys of tin/copper, tin/bismuth, tin silver; palladium/nickel/gold combinations.

The evaluation programme will include:

  • Component manufacture; wire-bondability, moisture ingression and tin whisker evaluation. Scanning electron microscopy will determine cause of ruptures in the heel of the lead.

  • Component assembly; solderability testing and process yield. Processability of these finishes can influence both component manufacture and assembly. These new coatings will require characterisation to gain consumer confidence.

Potential partners can obtain more information from: Dr Chris Hunt/Fleur Whitehouse. Tel: +44 (0) 20 8943 6065; Fax: +44 (0) 20 614 0429; E-mail:

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